package com.mk.property.filter;

import com.alibaba.fastjson2.JSON;
import com.mk.property.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器,支持通配符
    private static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //获取本次请求uri
        String requestURI = request.getRequestURI();
        log.info("拦截到请求:{}", requestURI);
        String requestURL = String.valueOf(request.getRequestURL());
        int indexEnd = requestURL.lastIndexOf(requestURI);
        String prefix = requestURL.substring(0, indexEnd);

        //定义不需要拦截的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**"
        };

        //判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
        if (check) {
            log.info("本次请求{}不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //下面是需要处理
        //判断登录状态
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录,用户id为{}", request.getSession().getAttribute("employee"));
            filterChain.doFilter(request, response);
            return;
        }

        //未登录
        log.info("用户未登录");
        response.sendRedirect(prefix + "/backend/page/login/login.html");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配,检查本次请求是否需要放行
     *
     * @param urls
     * @param requestURI
     * @return
     */
    private boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
